Optimization for Bending Collapse of Thin-Walled Twelve Right-Angle Section Tubes with Variable Thickness.

This study aimed to investigate the influence of variable thickness on the mechanical properties of thin-walled twelve right-angle section tubes (TTRSTs) through numerical characterization. This paper introduced the TTRSTs with different thicknesses for sides and webs. The three-point bending finite element model correlated with the physical test was built up and modified to find the lowest initial peak force (IPF), maximum specific energy absorption (SEA), and highest mean crushing force (MCF). Effects of variable thickness as well as impact location on the energy absorption performance of TTRSTs were investigated, suggesting that the energy absorption performance was more sensitive to side plate thickness changes than web plate thickness changes in web plate impacts. In addition, the TTRSTs with about 2.5 mm thickness demonstrated the highest SEA. Optimal Latin hypercube design (Opt LHD), response surface method (RSM), and NSGA-II were employed to optimize the TTRST multiobjectively under different impact loadings. The optimized results highlight that the TTRSTs can reach a 46.92% lower initial peak force or 2.61% higher MCF with minor SEA by selecting the appropriate thickness for impacts at different locations. [ABSTRACT FROM AUTHOR]